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Topic Review (Newest First)

12-11-2014 03:26 PM

rnman

Re: Equalizing AGM batteries

My opinions, use them at your own risk, and research them as you feel the need to before using them until you content you "get it".

AGM batteries are great for quick energy release and ease of charge, but equalizing them like you would a wet cell battery (flooded vs AGM "absorbed glass mat") has been a bad idea the two times I tried it (against my better judgement ). A little research on my end suggest that 14.7 volts is as high as these batteries should ever be charged, and that should only be with enough current/amperage to get the voltage there, but never more that 0.75 amps on a 6 volt - 3 cell, or 1.5 amps on a 12 volt - 6 cell battery regardless. Like someone else said, fully charge your battery, then maybe even float it at 13.5-13.6 volt and <100 milliamps for a couple of days to really saturate the battery, then equalize it. Never start equalize charging any battery until it has had a full charge done, and never do this inside your home or garage, but only outside or in a well ventilated shop with all the safety precautions that make sense.

The charging algorithms for AGM batteries do not exceed 14.7 in my Midtronics GR-8 charging system I don't believe (a 3000.00 charging system), nor do the voltages go as high in my Schumacher algorithms for AGM's as they do for "wet cell" batteries. That said: LISTEN, - BUT!!!!!, WATER FROM THE BATTERY ELECTROLYTE BEGINS TO SUBSTANTIALLY BE BOILED OFF AT ONLY 14.4 VOLTS, so if you go above this often or FOR A LONG PERIOD OF TIME ON AN AGM, or even on a sealed WET lead acid battery - you will eventually dry out one of the cells, and the battery will be no good, and the dry state could allow the battery to create and electrical arc and result in an explosion; I did not experience this on my AGM's, but I did dry out the cells most likely as both AGM's I tried to equalize a few times, lost ~ 2.1 volts o/v across the battery indicating a killed cell, and the battery sides shrunk in as though negative pressure from lost volume in that cell had been created. Bottom line in my opinion, if you must equalize your AGM, don't go above an average of 0.25 amps per battery cell (0.75 and 1.5 for 6v/3cell and 12v/6cell batteries respectively) and don't even do that unless your going to invest in a battery tester (Harbor Freight Tools sells one that is about $75 bucks that does just fine for measuring internal resistance and open voltage across the terminals (o/v). Use the tester to determine when equalizing is actually helping vs. hurting. If equalizing your battery doesn't decrease the internal resistance of the battery, improve it's resting voltage after a charge is completed and the battery rested for a 12-24 hour period, or for sure if equalizing is increasing your internal resistance, then your not doing your battery any favor by equalizing it unless your trying to put it out of it's misery. It's also great to use to track and assess the general condition of your batteries health and state-of-charge. The ohms resistance (< than 3 is excellent battery condition in my experience, 3-4 is very strong, 4-5 is still really good, 5-7 is starting to suggest the needs to be serviced or replaced, and over 7 is for sure a weak battery ready to let you down when you don't want it to. There's a lot of information and knowledge required to safely equalize a battery, so please be careful, do this at your own risk...(my opinions are mine and are "as is..." without any warranty of safety or efficacy). Battery care can be dangerous, so have eye and skin protection on, never do it without being able to get medical help for yourself, or without being able to access fire control/extinguishers. Just be damn careful. Safe boating!!!

My steps in synopsis:
1. Charge my battery completely
2. Float it at 13.5 - 13.6 volts for a couple of days
3. Measure the electrolyte specific gravity (can't do this in an AGM or Sealed wet Lead-Acid)
4. Equalize at less than 1.5 amps total on the 12v/ 6cell battery and 2.5 to 2.65 volts per cell (15 - 16 volts on a 12 volt battery) HERE IS WHERE THE VOLTAGE FOR AN AGM OR SEALED BATTERY IS RELAVANT BECAUSE YOU CAN'T REPLACE THE ELECTROLYTE OR MONITOR THE INDIVIDUAL CELLS
5. Recheck electrolyte specific gravity and quit equalizing when no further evidence of improvement is noted or if battery starts getting hot, or electrolyte becomes colored at all.
6. Determine if battery if good after 24 hours of rest following any charge or equalization.

AGAIN.....AT YOUR OWN RISK! THIS REALLY IS ONLY SAFE TO DO IF YOUR AUTOMATIC CHARGER HAS AN EQUALIZATION MODE (genius, xantrax, and progressive dynamics make automatic chargers that equalize) BECAUSE DOING IT MANUALLY WITH A DC POWER SUPPLY REQUIRES SOME KNOWLEGE TO AVOID INJURY, FIRE, EXPLOSION, OR EVEN DEATH!!! I wouldn't even do them on my boat, and I don't have a big boat...just sayin'. Take them out and do the equalization in a controlled environment!!!! Did I say...AT YOUR OWN RISK YET????

03-23-2011 11:19 AM

sea_hunter

This is the problem with mixing batteries. Some AGMs can handle equalization while others will just run away; all bad. I would suggest removing the connections to the ones that CAN be equalized (make sure the other batteries are fully charged) and equalize them with a separate battery charger as that will allow you to leave the settings alone on your charger or inverter/charger if you have one. Once equalized, disconnect the external battery charger and reconnect those batteries. This is why I caution most not to equalize any AGM until you read your manufacturers manuals, considering the average boater's electrical/electronic skills.

02-06-2011 02:04 PM

divicolouis

Thanks, I talked to a tech at lifeline and he said its ok to condition in the salon just ventilate well in case there is a release of hydrogen it becomes dangerous at only 4%! I'll wait till the weather warms up and I have to do some glass work on the companion way coaming.

01-25-2011 08:02 AM

Maine Sail

Quote:

Originally Posted by sea_hunter

WARNING: Do not equalize gel or AGM batteries!!!!!!!!!!!!!!!!!!
one of two things might happen; screw the batteries (burn out) or screw the boat (burn up). Read your battery manual 1st.

Please read the entire thread before posting!

SOME AGM batteries CAN be equalized and considering the short lives this type of battery has had in the marine market many Lifeline owners are darn happy Lifeline designed their batteries to withstand an equalizing or conditioning charge..

I will post this again:

Before you make factually worded statements like you did above, you should ideally freshen up your knowledge on the subject before posting.

Considering this thread was originally, back in 2006, about Lifeline & Deka/East Penn batteries, and Lifeline says equalizing is okay to do if the batteries are showing diminished capacity, and Deka says no then your broad based statement above is an unreliable choice of presented information. In a worst case scenario it might cause someone with Lifelines to buy new batteries pre-maturely, which could be an expensive mistake, before trying and equalizing / conditioning charge.

This is a DIRECT quote from Lifeline:

"Conditioning/Equalizing Charge: 15.5 volts for 8 hours. Conditioning/equalizing should only be done when the battery is showing symptoms of capacity loss. If conditioning/equalizing is necessary, first go through the normal charge cycle. Once the battery is as fully charged as possible, start the conditioning/equalizing charge.

To apply a conditioning charge, first go through the normal charge cycle to bring the battery to full charge. The conditioning charge should then be applied by charging for 8 hours. At 77°F (25°C), the conditioning voltage should be set at 2.58 VPC (15.5 volts for a 12 volt battery). The conditioning voltage at other temperatures is shown in Table 5-2. By using the temperature compensated conditioning voltage, batteries that are not in controlled temperature environments may be conditioned without bringing them to room temperature. If temperature compensation is not available, it is best to bring the battery as close to room temperature as possible before applying the conditioning charge.

For maximum battery life, a battery must be recharged to 100% capacity. Recharging to less than 100% may result in premature battery failure. Lifeline batteries are not covered under warranty if they are not recharged properly. For more information, please refer to our warranty policy."

A more accurate statement would have been to say that some manufacturers say it is okay to equalize AGM's and some or many others prefer that you don't. As always and as you said at the end read the manual or check with your manufacturer before equalizing AGM batteries. But some AGM's CAN be equalized!

Because each manufacturer has specific requirements for their own AGM's a blanket statement can not be made for all AGM batteries. Here is Trojan's statement on equalizing AGM's.

Direct quote from Trojan Battery:

WARNING: Do not equalize gel or AGM batteries.

If you had left your statement as "Read your battery manual 1st" it would have been accurate information. Clearly blanket statements do not always work as applied to all brands of AGM batteries and seeing as Lifeline is perhaps the #1 AGM maker in terms of marine market volume, here in the US, that means that a LOT of boaters can equalize their AGM's....

01-24-2011 11:15 PM

sea_hunter

WARNING: Do not equalize gel or AGM batteries!!!!!!!!!!!!!!!!!!
one of two things might happen; screw the batteries (burn out) or screw the boat (burn up). Read your battery manual 1st.

12-24-2010 12:33 AM

divicolouis

Maine Sail
I have 2 Lifeline 8D's AGM's under my salon settee which I believe need to be "conditioned" Would you recommend removing them from the boat before conditioning (they are 160lbs ea)

12-18-2010 03:36 PM

hellosailor

"As AGMs are "sealed" they should not be subjected to the "equalizing" conditions."
As Maine says, Lifeline is BUILT TO BE EQUALIZED. East Penn IS NOT. Saying all AGM batteries are the same, or should be treaeted the same, is like saying it's OK to drink the orange Windex because it looks just like Fanta and Nehi.

Could be they are different products under that pretty box, huh? For the price LifeLine charges, they can afford to build a stronger case that can take the strains of equalizing. Maybe it is better, maybe it is not, but it definitely is not the same product.

12-18-2010 02:03 PM

Maine Sail

Quote:

Originally Posted by dbackiel

As AGMs are "sealed" they should not be subjected to the "equalizing" conditions. Flooded lead acid can take the overcharging conditions that the equalizing subjects them to as they can vent. The AGMs venting are safety valves. Lead acid batteries should be equalized as the plates will build up scale and this reduces capacity. The AGM while "starved" is a lead acid but cannot be equalized. I have had AGMs and now use gel which because of a different electrolyte are so slow to sulfate that you don't even have to think about it.

Before you make factually worded statements like you did above, you should ideally freshen up your knowledge on the subject before posting.

Considering this thread was originally, back in 2006, about Lifeline & Deka/East Penn batteries, and Lifeline says equalizing is okay to do if the batteries are showing diminished capacity, and Deka says no then your broad based statement above is an unreliable choice of presented information. In a worst case scenario it might cause someone with Lifelines to buy new batteries pre-maturely, which could be an expensive mistake, before trying and equalizing / conditioning charge.

This is a DIRECT quote from Lifeline:

"Conditioning/Equalizing Charge: 15.5 volts for 8 hours
Conditioning/equalizing should only be done when the battery is showing symptoms of capacity loss. If conditioning/equalizing is necessary, first go through the normal charge cycle. Once the battery is as fully charged as possible, start the conditioning/equalizing charge.

To apply a conditioning charge, first go through the normal charge cycle to bring the battery to full charge. The conditioning charge should then be applied by charging for 8 hours. At 77°F (25°C), the conditioning voltage should be set at 2.58 VPC (15.5 volts for a 12 volt battery). The conditioning voltage at other temperatures is shown in Table 5-2. By using the temperature compensated conditioning voltage, batteries that are not in controlled temperature environments may be conditioned without bringing them to room temperature. If temperature compensation is not available, it is best to bring the battery as close to room temperature as possible before applying the conditioning charge.

For maximum battery life, a battery must be recharged to 100% capacity. Recharging to less than 100% may result in premature battery failure. Lifeline batteries are not covered under warranty if they are not recharged properly. For more information, please refer to our warranty policy."

A more accurate statement would have been to say that some manufacturers say it is okay to equalize AGM's and some or many others prefer that you don't. As always read the manual or check with your manufacturer before equalizing AGM batteries.

Because each manufacturer has specific requirements for their own AGM's a blanket statement can not be made. Here is Trojan's statement on equalizing AGM's.

Direct quote from Trojan Battery:

WARNING: Do not equalize gel or AGM batteries.

12-18-2010 12:49 PM

dbackiel

Ip32120

As AGMs are "sealed" they should not be subjected to the "equalizing" conditions. Flooded lead acid can take the overcharging conditions that the equalizing subjects them to as they can vent. The AGMs venting are safety valves. Lead acid batteries should be equalized as the plates will build up scale and this reduces capacity. The AGM while "starved" is a lead acid but cannot be equalized. I have had AGMs and now use gel which because of a different electrolyte are so slow to sulfate that you don't even have to think about it.

10-08-2009 09:11 AM

CKS

AGM's

Hi,
that's the article I read. I've decided to add another 100 watts of solar power to the 80 I alreadty have and replace the batteries; that should keep the problems away. I'll do all that next spring.

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